Machine-to-machine (M2M) communication is becoming an increasingly critical consideration in the development of future communication technologies. In M2M communications, machine type communication (MTC) devices such as smart meters, signboards, cameras, remote sensors, laptops, and appliances are connected to the communication network. These devices may differ dramatically from conventional communication devices. Many MTC devices are designed to transmit sporadic bursts of one or a few short packets containing measurements, reports and triggers, such as temperature, humidity, or wind speed readings. In most cases, MTC devices are expected to be installed in a fixed location or to have low mobility. MTC devices are typically low-complexity devices, targeting low-end (low average revenue per user, low data rate, high latency tolerance) applications. These devices often have severe limitations on power/energy consumption as well.
Because of these features, the M2M services defined by the 3GPP Long Term Evolution (LTE) standards and other communication standards place very different requirements on a wireless network from those of traditional services, such as voice and web streaming. These differences are compounded by the fact that wireless networks supporting M2M communication may be required to serve a significantly larger number of devices than is typical in conventional wireless networks, as MTC devices are expected to be cheap and widely deployed. As a result, designing for M2M/MTC communications in wireless communication networks creates several challenges and there is an increasing need for cost-, spectrum- and energy-efficient radio access solutions for M2M applications.
In conventional wireless communication systems, for example LTE systems, the processing of received data at the receiver (i.e. base station or relay node or other reception point) typically includes:                receiving the signal from a user equipment (UE) or other wireless device;        demodulating the received signal to a baseband signal;        applying OFDM demodulation and cyclic prefix removal to map symbols into different physical resource blocks;        descrambling the demodulated signal with a UE-specific sequence;        performing rate de-matching;        decoding the signal (e.g., at the physical layer, typically turbo coding), using a known channel de-coding scheme; and        confirming that an error detection check (e.g., a check cyclic redundancy check (CRC)) is successful.        
If the CRC check succeeds, the sequence of bits (usually in the form of transport blocks) are passed from the physical layer to the media access control (MAC) layer for further processing. The receiver may also transmit feedback information (e.g., an acknowledgement (ACK) indication) confirming successful reception. If the CRC check fails, the received signal is maintained at the receiver and a re-transmission may be requested. For example, the receiving node may request re-transmission by sending a feedback information indicating the transmission failed (e.g., a negative acknowledgement (“NACK”) indication) to the transmitting device.
Given the currently available solutions and the constraints associated with supporting MTC services, providing coverage to a large number of MTC devices would likely require a massive deployment of base stations (macro, micro, pico or femto stations) or relay nodes, or the use of extremely powerful base stations with advanced receivers that possess several receiver antennas capable of collecting the weak signals from MTC devices and of using advanced radiofrequency processing to overcome the difficulties. However, both of these solutions would require great expense and significant installation effort by network operators. As a result, there is a need for efficient communication methods for M2M systems that can more effectively handle a dramatic increase in the number of MTC devices to be supported and the amount of MTC traffic.